using existing hull as mold?

[Rippin Lips]

hello, i was just wondering if there is anyway to use an existing hull as a mold, or use to create a mold if so....

1)will it ruin my existing hull, is there anything to coat it with?

2)if used to create a mold, how would i go about doing so?
(as in materials and instruction...any links would help.)

please bare with me as i am the newest of newbies but willing to learn.....thanks

[Eric Sponberg]

You can, but that is known as "stealing the design" and is against federal law. It is also unethical. The 1998 Vessel Hull Design Protection Act, otherwise known as the "anti-splash law", prohibits taking molds of existing boats unless the person doing the molding has the permission of the owner of the design. Unless and until you get that permission, you can stop your inquiry right here.

Eric

[Rippin Lips]

i appreciate your rapid reply and thanks for the headsup on the laws and all.....my boat was built by a friend of mine before he passed, i guess it was just to see if he could do it, it is however the only boat he's built like that so im sure the laws dont apply as he was not a manufacturer. i would not have brought my inquiry to the forums if i thought that there were legalities and such. i have one of two boats that he has built. the boat is great and i have never had any problems with it in the 6 years that ive had it, all i know is that he built a wooden hull and layed fiberglass over it to come up with the hull i am using now which is completely fiberglass no wood. i just would like to know the steps to duplicate it and maybe add some extras. once again i appreciate your input on the "anti-splash" laws as i was totally un aware of it, i am not a builder but i do ant to learn an i seek some sort of "online training" be it through links or input form others....thanks again

[marshmat]

Your friend's estate probably owns the design now and it shouldn't be too hard to talk it through with the appropriate lawyer. It is a Very Bad Idea to attempt this without appropriate legal approval.

It is technically feasible to make a female mold from a hull. This is how they're made in the first place, from an exact male plug of the hull. Find a good book on fibreglass construction; build a mold as for a new design but use your existing hull as the plug. The 'plug' must be coated with a release agent; if the whole shebang is done properly it will not damage the existing hull.

[Rippin Lips]

thanks marsh, and my friend had no family really, at leat none that gave a ****. he was just a normal fishing guy like me just trying to come up with something that worked. i know there was nothing legally on the boat aside from the basic registration and that was it. just a backyard build, but i will definately check into it...but if nothing comes up, is the mold made of the inside of the hull, or the outside?

[marshmat]

the outside shape of the hull is what matters... to get a mold from a hull plug, you carefully prepare the outside and lay a very hefty laminate over the upside-down boat. You'll need to read up on the process before you start as it's far too involved to explain in detail here.

[Eagle Boats]

Just to add my 2 cents, it will take a lot of work to get the hull (which is called a plug) ready to make a mold from. First, you should make sure that the dimensions on either side of the hull are identical. I have seen plugs that were off by as much as 3 inches in places from one side to the other. In addition, after you have done that, there will be a tremendous amount of fairing and finish work necessary to get the plug ready to pull a mold from. If you are sure that the boat you intend to build will have market appeal, go for it. Before you start this endeavor, you may want to try making a small mold first to make sure that you really want to go forward. Anyway, best of luck to you.

[Rippin Lips]

thanks eagle, didint realize how intensive it could be, i thought it was just about laying lots n lots of fiberglass over the prepared hull until its twice as thick as you would intend the new hull to be.......well i guesss that will be out of the question now but i do have another one.......what do you think about plywood boats? i was thinking about buying a design kit from bateau.com. their smaller designs are for beginners but all of them look really good and they have many different styles. its a stitch and glue build but my understanding is that you can re-enforce as much as you want with fiberglass.

[gfinishline]

Hey 'Lipps' why do you PM me (more than once) and ask questions, then ask the same questions (in a different way) here? Did you not like my TRUTHFULL answers? Why would anyone waste their time with you, when you are all over the web bugging everyone? I have been doing tooling since 1972 and it just isn't as easy as everyone would like it to be. Step up or step back, but just don't be a BS'er with our time and experience. Those of us that have made molds know that it is NOT AN EASY JOB! YOU won't find any "magic way" to make it easyer! Why do you think we (people who know how) are here looking for cheap molds? AND! I told you the mold had to be THREE TIMES AS THICK AS THE PART IT MAKES! Why state 2 times?

[Rippin Lips]

what the hell are you talkin about? i dont ebven know who you are....i have never PMd you once so what are you talking about "more than once"? get your facts straight before bashing... ive never PMd anyone i may have emailed a few people and dont remember who but i sure as hell dont recognize your name....besides, im asking for advice not demanding instruction...i thought this site welcomed new builders and the inquisitive alike, yet you act like im an annoyance... ill accept your feedback when i ask for it. til then go take your frustrations out somewhere else

[gfinishline]

Are you nuts? Your 'name' sgt slapaho, is all over my mail, along with "Rippin lips" @ Cox.... I wanted to help you, but you seem to be a little off base! Don't bother to respond, I don't need people (users) like you! I know how to make molds and boats! I do it for a living.

[Wynand N]

Rippin Lips, gfinishline

This is a public forum and I for one is against personal attacks amongst members. If you gentleman have a difference of opinions, please use the PM's or Email and keep it private and among'st yourselfs....

All of the best

[gfinishline]

You are correct Sir. I seek the truth and only offer my true experinces in these fields. I do not condone what I feel Mr"Rippin Lips" is doing. He has asked me a number of questions (at my mail), I have answered ALL of his questions. He then comes back here, and 'plays dumb', asking the same questions and getting the same answers, over and over. If we (who have made molds and parts) are not giving the answers he WANTS TO HEAR, then I am sorry, but why not be 'up front' and state the fact that he has contacted others, and has a good idea of how molds/ mold making work. This kind of person makes it more difficult for the 'true information seekers', to open up the 'mind vaults' of knowledge. I would like to help anyone who asks, but not 'go around and around' with those who waste my time. Has he contacted any of you?

[alex livingston]

Rippin, Ive been a backyard boat builder for a few years and if your gonna make a one off boat, try building models out of cardboard.This allows you to fool around with designs.and then building the protos out of fiberglass sheets that can be made on a plywood/formica table. We are currently laying up a thirty eight foot fishing boat with flats that we layed out on a forty foot table. THree years ago we finished a thirty four foot boat that works sweet!

Check out Panamasportsman.com under the Magoo Project...

[yokebutt]

Hey, gfinishline, you should know as well as I do, the best revenge is just to tell him to go ahead......

Yokebutt.

[JEM]

i was thinking about buying a design kit from bateau.com. their smaller designs are for beginners but all of them look really good and they have many different styles.

Carefull with this. If you're doing this just for your own boat and want to try a "one off" (the term for what you want to do) then you'd be just fine.

But if you want to sell these, then bateau will probably want a fee for each hull you sell.

Plywood building via Stitch and Glue is a nice technique to get a hull for your own personal use. But building a design meant to be a plywood hull and using it for a plug is a bad idea. I know because I did it by designing and building the prototype for www.tailboats.com. We originally set out for it just to be a plywood and fiberglass prototype hull for testing. Then we were going to build a second hull to be used as a plug.

Well to be honest, I grossly underestimated the time it would take. The design was complex and some modificatins were made after the initial testing too. Tailboats needed to get their hull to market so no time to build a second plug. We cleaned up the original prototype and took it a local fiberglass shop that will do the finishing work and pull the molds. It turned out very nice but a lot of hours and sweat went into it going that route.

Quite a hard learning experience but I'm well schooled if I do that sort of project again.

Anyway back to my original train of thought. I say build something stitch and glue to get the experience of building. That will give you a good indication if you want to try your luck at building a plug. You'll gain some good insight and the quality of your second project will be that much better. Then if you want to build a plug, get with a designer and tell them you want to build a plug.

If the designer is worth their salt, then they will provide a method and design that can be built to ensure the hull is fair and symetrical. You could strip build with a strongback or a Stitch and Glue with a strong back will provide the most accurate results.

Other option is to have a plug 5-axis CNC cut from foam. The cheapest I've found for a smaller hull is about $5k. And that's just for milling. You still have to sand and finish to be ready to pull molds.

Good luck!

[Rippin Lips]

excuse me if i didnt remeber you gfinish, i didnt recognize the name. the only one i have ever talked to about building a mold was a person by the name of blackhawk or something like that.....dont attack me! i'm new at this and i have never, ever built a boat before so i use this site as a discovery tool. i publicly question others because your reply to to my queries are very short and not descriptive. dont get me wrong, i appreciate the answers you did give me but because i ask a little more in the forums to get a straight answer is no reason bash me in your first post. once again, i know nothing thats why i seek advice. that's all i came to this forum for and i thought that this forum was all about helping the unknowing and for this other guy down here to say to just tell me to do it is not what ive come to expect out of a help forum. i'll keep in mind not to ask you 2 for any advice.....

SLAPPY.

[Rippin Lips]

i do appreciate your advice also. i've done some research on mold building since the last time i was here and have come to realize that it is definately NOT the route i want to go. ive recently ordered the plans and precuts for an 18' dory which is very similar to the boat i really would like to build (panga) from bateau.com. it looks very tailored to the new and i look forward to starting my project. upon completion i still do hope to find a panga mold ( and not build one) so i can learn to build that way too.....once again thanks alot.

[solrac]

May you guys use this homemade method:
1. polish & wax the original hull
2. Newspapers, old newspapers, a lot of them & a pot of vaseline (not for that you're thinking, you freaks). the idea is to make a thin foil of paper (3 to 4 papers thick). let it dry overnight
3, get some metal wire, the type used for fences,(chicken mesh) some construction reinforcement iron bars & stick them to form a kind of a skin.
4. Concrete or plaster about 2.5 to 5cm (1" to 2") to cover all the stuff
let it complete drying process (depending on weather/temp, a couple of days to a week)
5. Now it came the real work, let's turn the monster upside down. get help, a lot of help, (even a crane or a hydrolift the concrete mold weights about 12/15kg/m2, a 3.70 laser hull mold is about 100kg, not recomended for a 30" sailboat) Caution: keep children away & think twice while planning the manoeuver...
6. with a reasonable long wood stick & a piece of rope, tie to some hanger in the hull & softly try to unmold the original hull, (I grant, it's not so dificult, don't be scared, it pops out really easy, the newspaper & vaseline are gorgeous)
So, you ended with a mold very similar to the original hull, in case any break, can easily fix with some plaster & sanding....
For making a new hull on the mold, follow the same process inversely, sand & clean the mold, fix w/plaster any hole, apply newspaper& vaseline, and you're ready to glue the epoxi.
I've been using this method for 20 years...
good luck

[Rippin Lips]

wow Solrec, didnt know this thread was still read. thanks for the tip. I'll give it a try on a small skiff.

[MrBlack]

Rippin Lips IM very sorry to read this thread and to hear/read the anal idiots reply in the way they did.
If you take another boat and copy it fine do it and learn from it as the boat will probably be vry average.
If its very good and your lucky then great.
Im sure these anal people do not think twice when downloading mp3's.
gfinishline if someone wants to pm you then ask more questions else where so what?
That means they are seeking more infomation which is a good thing.
Oh and you tell no one nothing you inform.
Get over yourselves who the f do you think you are.

[MrBlack]

im SERIOUSLY cheesed off as i printed this trash out thinking I was going to get some quality insight.
What a waste of time.

[Rippin Lips]

im just a newbie trying to find out how this is done, i am NOT trying to copy a boat, i am not trying to build to sell. just wanna learn so i can eventually build one of my own. i just came back to look around for anything new, my brother and i are entered into a contest to build a boat in 4hrs during harbor days just for fun to see who can make it across the harbor and back. I feel that could be a start.

i DO wanna learn and still seek a step by step tutorial if at all possible, thanks for the replies.

[MrBlack]

Good luck to you matey I wish you well in your dream.

[solrac]

Hey.... nobody is talking about infringing copiright laws, this metod was applied by me a couple of times for repair purposes only....we used to think it's easier to make a new hull for an optimist or laser that was hardly broken by the kids at a regatta than trying to repair it. the hulls already made with this method were mostly used for kid sailing at a sail club here....
I also used this method once on a development of a homemade hull, because it's esayly modifiable...

[solrac]

Rippin Lips IM very sorry to read this thread and to hear/read the anal idiots reply in the way they did.
If you take another boat and copy it fine do it and learn from it as the boat will probably be vry average.
If its very good and your lucky then great.
Im sure these anal people do not think twice when downloading mp3's.
gfinishline if someone wants to pm you then ask more questions else where so what?
That means they are seeking more infomation which is a good thing.
Oh and you tell no one nothing you inform.
Get over yourselves who the f do you think you are.

Oops, kid, have you argued with your boyfrend?
No need to be so rough, someone asked for a method & I answered that's all.
Of course, the results are average, as you stated but the hulls I've done in the past with this method were for training purpses only, they can't compete with vacuum molding, but the "average" hulls were not too bad....